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Voltage Pentode ·Pentode

NF4

Telefunken RF pentode designed for series-heater operation associated with 25 V starter-battery mobile radio equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
P8A
Base pins
8
Nominal heater
12.6 V / 195 mA

Description

Telefunken NF4 indirectly heated RF pentode designed for series heater operation from 25 V starter batteries.

Socket description

European 8-pin side-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
P8A
Base pins
8
Nominal heater voltage
12.6 V
Nominal heater current
195 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
1800000 Ω
Transconductance
0.00215 S
Max plate voltage
200 V
Max screen voltage
150 V
Max plate dissipation
1.5 W
Max screen dissipation
0.3 W
Max cathode current
6 mA

Published ratings and characteristics were promoted when unambiguous; additional operating values are preserved in TUBE_SECTION_PARAMETER.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

194X Wehrmacht Rohren

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Input capacitance

    7 pF

  • Output capacitance

    8.3 pF

  • Grid-plate capacitance

    - to 0.003 pF

Other

  • Plate current

    3 mA

    Ua=200 V; Ug2=100 V; Ug1=-2 V